ASU MIC 205 EXAM 1 questions with correct answers

Hershey and Chase performed an experiment in order to determine how bacteriophages infect bacteria. What did they find? CORRECT ANSWER The bacteriophage injects DNA into the host cell. This was found because, after centrifugation, the pellet was radioactive The largest difference between a Gram + and Gram - bacterial cell is: CORRECT ANSWER The gram + cell has a much thicker peptidoglycan layer Why does a Gram + cell stain blue/purple in a gram stain? CORRECT ANSWER The Gram + cell stains blue/purple because crystal violet remains trapped in the thick peptidoglycan layer. dormant with no detectable metabolism. CORRECT ANSWER Endospores You have bacteria in need of staining, though you are aware that they have capsules. How do you stain them? CORRECT ANSWER Negative stain, such that the bacterial capsule remains clear.